Explosive assembly



y 9, 1962 N. J. LEA 3,036,523

EXPLOSIVE ASSEMBLY Filed July 10, 1958 T TJEII.Z:

. simultaneously as a single charge.

3,636,523 Patented May 29, 1962 3,036,523 EXPLGSIVE ASSEMBLY Norman J. Lea, Bellaire, Tex., assignor to Texaco Inc, a corporation of Delaware Filed July 10, 1958, Ser. No. 747,643 6 Claims. (Cl. 102-24) This invention is concerned with explosive assemblies in general, and more specifically is particularly concerned with an explosive assembly structure that is especially adapted for use in seismic work.

In seismic exploration work, it is common practice to employ charges of explosive which are sufficiently large so that more than one stick of dynamite, or other high explosive, is employed. Under these circumstances a string of explosive charges are fastened together and detonated Such a string of explosives must be made up at the surface of the ground prior to or during, lowering of the charge into a shot hole, or other cavity that has been prepared in the surface of the earth to receive the charge. When a number of sticks of explosive are fastened together thus to make up a substantial charge for exploding underground, problems have been encountered by reason of the weight of the separate sticks of dynamite that becomes cumulatively quite high and exerts strong tensile forces between sticks at the upper end of the complete string of explosive charges. Heretofore, various arrangements and ideas have been suggested for overcoming these problems. Among such suggestions is included the wrapping of each stick of explosive with a helical thread structure, and then providing a sleeve having female thread structure on the inside thereof to match the thread on the outside of the charge. However, such an arrangement had a bad tendency to become loosened, or unthreaded, after the charge string had been made up. Consequently adjacent sticks of explosive would become separated from one another, and sometimes one or more of the sticks would fail to detonate.

Consequently it is an object of this invention to provide structure for an explosive assembly, which overcomes the above indicated difiiculties.

Another object of this invention is to provide apparatus such that a string of explosives may be put together quickly and easily, in addition to the fact that adjacent sticks of explosive are held together in sung abutment, even under loading tension.

Another object of the invention is to provide a sleeve element for use with sticks of explosive, such that a plurality of sticks of the explosive may be fastened together by means of the sleeve with the ends of the explosive sticks held securely in close abutment to one another, and then they may be unfastened again if desired.

Another object of this invention is to provide a sleeve structure for connecting a plurality of sticks of explosive together, which has structure such that the wire leads for the detonator may be protected within the sleeve as the string of explosive is made up and lowered in the hole. Another object of this invention is to provide a sleeve structure for connecting a plurality of sticks of explosive together, so constructed that the sleeves may be shipped concentrically located about sticks of explosive.

Briefly the invention is concerned with an explosive assembly which includes an elongated container filled with explosive material. The said container is elliptical in overall cross-sectional configuration, and the explosive assembly includes a sleeve for connecting two of said containers together in end to end abutting relation. The said sleeve is elliptical and has the minor axis inside diameter thereof, substantially equal to the maximum outside diameter of said elliptical container. The assembly also includes lug means on the inside surface of said sleeve.

In addition the assembly includes complementary groove means on the outside surface of said container. The said lug and groove means are so constructed and arranged that said sleeve may be coupled to said container by insertion of said container within said sleeve longitudinally until said lug and groove means are at the same longitudinal location, and then by rotating said container ninety degrees relative to said sleeve.

A preferred embodiment of the invention is described below in more detail and is illustrated in the drawings, in which:

FIG. 1 is a side elevation, illustrating a string of dynamite sticks made up into a unitary charge;

FIG. 2 is a fragmentary, enlarged side elevation, partly broken away in section and illustrating the structure of a sleeve according to the invention, 'but viewed at ninety degrees relative to the FIGURE 1 view.

FIG. 3 is an enlarged, fragmentary side elevation, illustratiing the structure of one end of a stick of explosive formed in accordance with the invention, and also viewed at ninety degree relative to the FIGURE 1 view.

FIG. 4 is a somewhat less enlarged side elevation, illustrating a stick of explosive formed annd constructed in accordance with the invention, and viewed at the same side or one hundred and eighty degrees from the FIG- URB 1 view;

FIG. 5 is a transverse section view taken at the lug structure of a sleeve and including an end view of a stick of explosive located concentrically within the sleeve; and

FIG. 6 is a transverse sectional view similar to FIG. 5, but with the stick of explosive turned into locking engagement with the sleeve, and including a pair of cap wires within the sleeve.

Referring to FIG. 1 it is pointed out that there is illustrated a string of explosive containers 11 (sticks of dynamite) that are fastened together in abutting relationship by means of a plurality of sleeves 12 into which the containers 11 are inserted. There is also shown, a pair of cap lead wires 13 that extend down inside of the sleeve 12, as will be more fully explained below.

Referring to FIGS. 2 through 6, the details of the structure involved in the containers and the sleeves, will be pointed out.

It is contemplated that the containers 11 and the sleeves 12 will be constructed of appropriately heavy paper that is coated with wax for moisture proofing. With such construction the shapes can be formed by pressing with dies, or in some other feasible manner, prior to the coating with wax. The wax coating then adds stiffness, especially to the sleeves. Of course the material employed is not necessarily limited to paper. However, an economical commercial form for sticks of dynamite is in paper wrappers, or containers.

It is to be noted that the containers 11 and the sleeves 12 are both elliptical in their overall cross-sectional configuration. Toward each end of every container 11 there is located, diametrically opposed to one another, a pair of substantially identical grooves 16. These grooves 16 each is symmetrically located on the surface of the container 11 about the major axis thereof. Furthermore, these grooves 16 are each formed so as to be deepest at the center and tapered outward therefrom to become flush with the surface of the container 11.

Located on each of the sleeves 12, so as to extend inwardly from the inside surface thereof (see FIG. 5 there is a pair of lugs 20. These may be formed by being pressed in after the sleeve has been first wrapped, or otherwise formed as indicated above. Consequently there are indentations on the outside surface of the sleeve, where each lug 20 is located. Each individual lug 20 is symmetrically located about the minor axis of the sleeve 12 and is situated diametrically across from the other. There are a set of these lugs 20 near each end of each sleeve 12 so as to be accommodated by the corresponding grooves 16 of a container of explosive 11. Furthermore, the location of the lugs 20 is such that the positioning of two containers 11, one from either end of a sleeve 12, will cause the containers 11 to be abutted in snug contact with one another, at the adjacent ends thereof.

' It will be noted that there is a protuberance 23 (FIG. 2) that is located at the center along one edge of each of the lugs 20. Similarly, along a corresponding edge of each of the grooves 16, there is an indentation 25 (FIG. 3).

One edge of each of the grooves 16 is flared outward from the center of the groove, as indicated by reference numbers 28 and 29 (FIG. 3). These flared edges 28 and 29 of each groove 16, are preferably located on the edge that contains the indentation 25. This structure provides for aiding in the alignment of the lugs 2%) with the grooves 16, when the sleeves 12 are being coupled, or interlocked with the containers 11.

It will be appreciated that the dimensions illustrated in the drawings are exaggerated for the purposes of illustration. However, within practical limits, the major diameter outside dimension of the container 11 is at least equal to the minor diameter inside dimension of the sleeve structure 12, as clearly illustrated in FIG. 6.

It will be appreciated that other shapes than elliptical is employed. Among the benefits that are gained from the use of an out of round structure is included the ability to readily insert a container 11 within one of the sleeves 12 with clearance therebetween, as is clearly illustrated in FIG. 5. This means that in addition to ease in handling during the making up of a string of explosive charges prior to detonation, the shipping of the sleeves 12 may be carried out in a space saving, compact manner by inserting a sleeve 12 around each container 11, prior to shipment thereof. Among the advantages thus gained is the ability to ship the sleeves 12 in a secure manner, saving space and at the same time avoiding damage to the sleeves.

Among additional advantages which may be gained by this invention, is the ability to provide an easy to operate, and secure interlock structure, for holding a pair of containers in snug abutting relation. Thus the assembly of a string of charges may be carried out by merely inserting a container 11 into one end of a sleeve 12 until the grooves 16 are in longitudinal alinement with the lugs 20, and then by rotating the container "11 relative to the sleeve 12, through ninety degrees, until the protuberance 23 matches with and engages in the indentation 25. It will be noted that the flared edges 28 and 29 on each groove 16, act to provide a longitudinal movement of the container 11 toward the center of the sleeve 12. This forces the second container 11 to. be inserted in a coupling sleeve 12, to press against the container already in the sleeve.

In FIG. 4 it will be observed that there is illustrated an indicating line 33, applied to the container 11 on the outside surface thereof so that it will be readily observable when the container 11 .has been inserted intoa sleeve 12 for the desired distance. This indication 33 might take any feasible form. It is most helpful when the first of two containers 11 is inserted into a sleeve 12. Thus a container 11 will be inserted in a sleeve 12, with their major and minor axis in line with one another, until the edge of the sleeve 12 lies adjacent to the indicator 33 on the container 11. Then the container and sleeve may be rotated ninety degrees relative to one another, for lockin-g engagement, since the lugs 20 will be at the same longitudinal location as the grooves 16.

The structure involved in this invention eliminates the need for applying half hitches with the cap leads around the charge string, as a string of explosive is made up. Furthermore, the cap leads 13 are protected by being located inside the sleeves 12, as the string is made up. This is readily accomplished by. reason of the elliptical configurations of the container 11 and the sleeve 12, so that there is ample space for the cap leads 13 when the container 11 has been rotated into interlocking relationship with the sleeve 12.

Another advantage that may be gained by this invention is that, as a string of explosive charges is made up and prepared for loading in a shot hole, an additional sleeve 12 may be employed at the upper end of the string and it will act as a protector for, and aid in holding the loading pole guide, when the string of charges is attached to the loading poles for loading in the shot hole.

It will observed that in addition to the ease with which a string of charges may be made up, by the use of structure according to this invention; the same string may be unmade, if desired, by merely reversing the process and twisting the containers 11 back or forward ninety degrees relative to the sleeves 12 in which they are attached. This has a great advantage in that the size of a charge may be'changed after it has been made up. At the same time the string of charges when made up is securely held in lengthwise abutment and consequently a complete detonation of the entire string of charges is insured.

It is pointed out that as a string of charges is made up, the cap leads 13 may be readily inserted inside of the sleeves 12, by merely holding the leads 13 close alongside of each container 11 on the flattened sides thereof, i.e. along the minor axis. In this way, there will be sufficient room within the sleeve 12 to receive the charge in addition to the cap leads 13, and then as the interlocking connection between sleeve 12 and container 11 is effected, the cap leads 13 will move into the space formed between sleeve 12 and container 11 so that no binding effect will be had.

It may be noted again that the dimensions shown in the drawings are not to scale, and in practical application the sleeves 12 will probably form an easy sliding fit around the containers 11 when they are aligned with major and minor axes coinciding. But, the sleeves probably will be somewhat sprungout of their original shape as the containers 11 are rotated ninety degrees within the sleeves 12.

While a particular embodiment of the invention has been described in considerable detail in accordance with the applicable statutes, this is not to be taken as in any way limiting the invention, but merely as being descriptive thereof. a i

What is claimed as the invention is:

1. An explosive assembly including at least two elongated containers filled with explosive material, said containers being substantially elliptical in transverse crosssectional configuration, with a maximum and minimum transverse dimension, a sleeve for connecting two of said containers together in end to end abutting relation, said sleeve being open and having dimensions such that the minimum inside transverse dimension is not more than the maximum outside transverse dimension of said containers, first symmetrical interlock means on the outside surface of said containers, and second complementary symmetrical interlock means on the inside surface of said sleeve for cooperating with said first interlock means for engagement from either direction of rotation, whereby said containers may be locked to said sleeve to prevent relative longitudinal movements therebetween after said first and second interlock means have been engaged.

2. An explosive assembly including at least two elongated containers filled with explosive material, said containers being elliptical in outside transverse. configuration, a sleeve for connecting two of said containers together in end to end abutting relation, said sleeve being open and elliptical in transverse configuration and having the minor axis inside diameter thereof not greater than the maximum diameter of said elliptical containers, lug means on the inside surface of said sleeve, complementary transverse groove means on the outside surface of said containers, said lug and groove means being so constructed and arranged that said sleeve may be coupled to said container by insertion of said container within said sleeve longitudinally until said lug and groove means are at the same longitudinal location and rotating said container ninety degrees relative to said sleeve.

3. An explosive assembly including at least two elongated containers filled with explosive material, said containers being elliptical in outside transverse configuration, a sleeve for connecting two of said containers together in end to end abutting relation, said sleeve being open and elliptical in transverse inside configuration, a paifof diametrically opposed lugs extending inwardly from the inside surface of said sleeve and located at the extremities of the minor axis thereof, a pair of diametrically opposed transverse grooves on the surface of said container at the major axis thereof, said lugs and grooves having complementary structure whereby said container may be inserted in said sleeve with the major axis in alignment until the lugs and grooves are located longitudinally at the same place and then said container may be rotated ninety degrees to engage the lugs in the grooves.

4. An explosive assembly including at least two elongated containers filled with explosive material, said containers being elliptical in outside transverse configuration, a sleeve for connecting two of said containers together in end to end abutting relation, said sleeve being open and elliptical in transverse inside configuration, a pair of transverse diametrically opposed arcuate bands extending radially inward from and tapering into the inside surface of said sleeve, said bands being located symmetrically about the minor axis of said sleeve, a protuberance centrally located on an edge of each of said hands, a pair of transverse diametrically opposed arcuate bandshaped grooves in said containers, said grooves being recessed radially inward from and tapering outward into the surface of said containers, said grooves being located symmetrically about the major axis of said containers, at least one edge of said grooves being flared outward from the center line of the groove to facilitate registration of the grooves with said bands, and an indentation centrally located on a corresponding edge of said grooves for registration with said protuberance when said sleeve and said containers are in interlocked registration with one another.

5. An explosive assembly in accordance with claim 4 further including indicator means on said "containers for indicating the amount each said container is to be inserted Within said sleeve to bring said bands and grooves in registration prior to rotating said sleeve relative to said container to cause the interlocking registration thereof.

6. An explosive assembly in accordance with claim 5 wherein said container and said sleeve are constructed of cellulosic material.

References Cited in the file of this patent UNITED STATES PATENTS 878,818 Miller et a1. Feb. 11, 1908 1,917,540 Pearsall July 11, 1933 2,224,565 Flude Dec. 10, 1940 2,403,488 Bennett July 9, 1946 2,413,862 Cohan Jan. 7, 1947 2,415,422 Fogg Feb. 11, 1947 2,429,079 Smith Oct. 14, 1947 

